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    <title>Document</title>
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    <script>
        // 1. 新建 FormData 对象
        var fd = new FormData()
        // 2. 为 FormData 添加表单项
        fd.append('uname', 'zs')
        fd.append('upwd', '123456')
        // 3. 创建 XHR 对象
        var xhr = new XMLHttpRequest()
        // 4. 指定请求类型与URL地址
        xhr.open('POST', 'http://www.liulongbin.top:3006/api/formdata')
        // 5. 直接提交 FormData 对象，这与提交网页表单的效果，完全一样
        xhr.send(fd)
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                console.log(JSON.parse(xhr.responseText));
            }
        }
    </script>
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